Electronic power batteries must typically be properly installed in the electronic devices or products that make use of such batteries. Proper installation is commonly achieved through the use of written instructions or by using graphical directions on or in the product near or in the battery receiving area, such instructions or directions identifying the proper battery orientation for correct electrical polarity. Users often follow such instructions correctly, but at times the graphics may be difficult to see as they may have been molded directly into or as part of the product housings or the directions may have been printed on what may appear to be increasingly smaller labels. As a result, battery problems and product damage may occur. When batteries are disposed within an electronic product with incorrect polarity, the best case may be that the product simply does not work. In worse cases, batteries can overheat and leak, which can thereby cause permanent damage to the electronics, destroy the product, or cause a fire or explosion. Thus it would be desirable to achieve a solution to protect products from incorrect battery installation.
Some current methods of protection involve preventing electrical contact from occurring based on the battery terminal shape. This approach works, but if a product does not work after installing batteries, the user cannot immediately determine whether the cause is incorrect battery installation or dead or otherwise inoperable batteries. The user must then check that the batteries are installed correctly. Other methods include adding electrical current protection circuitry which may involve use of one or more diodes, rectifiers, transistors or other components. Such electrical circuitry would typically then allow current to only flow in one direction, protecting the product if the batteries are incorrectly installed. Such circuits are, however, known to reduce the supplied voltage and sap battery life by as much as 10-15% or more, and such circuitry may also be fairly expensive.